Towards Zero Retraining for Multiday Motion Recognition via a Fully Unsupervised Adaptive Approach and Fabric Myoelectric Armband

Surface electromyogram pattern recognition (EMG-PR) requires time-consuming training and retraining procedures for long-term use, hindering the usability of myoelectric control. In this paper, we design a fabric myoelectric armband to reduce the electrode shifts. Furthermore, we propose a fully unsupervised adaptive approach called hybrid serial classifier (HSC) to eliminate the burden of retraining over multiply days. We investigated the performance of our approach with a dataset of ten types of forearm motion from ten male subjects over eight weeks (total ten days, including: from day 1 to day 7, day 14, day 28, day 56). The average inter-day classification accuracies of HSC without any new retraining data are 86.61% when trained exclusively with the first day's EMG data, and 94.77% when trained with other nine days' data. We compare our proposed HSC algorithm with linear discriminant analysis (LDA) without recalibration (BLDA) and supervised adaption LDA (ALDA) with just one trial of new retraining data. The inter-day classification accuracy of HSC is significantly higher than that of BLDA and ALDA. These results indicate that our novel armband sEMG device is feasible for long-term use in conjunction with the proposed HSC algorithm.

Automated summary

This paper presents a novel approach for myoelectric control by designing a fabric myoelectric armband to reduce electrode shifts. A fully unsupervised adaptive method called hybrid serial classifier (HSC) is proposed to eliminate the need for retraining. The performance of the approach is investigated using a dataset of forearm motion and compared with other algorithms, showing higher classification accuracy.